Ensure byte and short values are sign extended before boxing.
Ensure byte and short values are sign extended before boxing.

Change-Id: Ib97b933eaceffe71f19affb22bec030f13516c2f

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst